Preheat oven to 300ºF. Toss together oats, almonds, pumpkin seeds, coconut, cinnamon, and salt in a large bowl. Stir in oil and syrup.
Divide mixture between 2 large rimmed baking sheets and spread out evenly. Bake until golden and toasted, 40 to 45 minutes, stirring every 10 to 15 minutes and switching pans from top to bottom and front to back halfway through.
Immediately transfer granola to a large bowl and let cool completely, stirring occasionally. (Granola will crisp as it cools.) When it’s cool, toss in raisins, if desired. Store leftovers in an airtight container for up to 2 weeks.